A cave in Phong Nha-Ke Bang National Park. Photo by Nld.

The new caves, which have a total length of 3.55 kilometres, were found in the team's latest survey in March this year.

Seven of the newly found caves lie in the Phong Nha-Ke Bang National Park, seven others in the park's buffer zone, and the remaining 11 are scattered in the surrounding area. The caves have a length ranging from 30-572 metres each.

The four longest caves include Va Cave (516 metres), 12/2 Dry Cave (404 metres) in Phong Nha-Ke Bang National Park, Vuc Hung Cave (430 metres) in the park's buffer zone, and Ong Dau Cave (572 metres) in Tuyen Hoa District.

Park Management Board Director Pham Hong Thai said in-depth surveys and studies are needed to clarify the value and make accurate judgments in preserving and sustainably using landscapes and caves.

Last year, the team also found 22 new caves running for 11.70 kilometres in the area.

Howard Limbert, the leader of the team, said that the new caves are mostly wet, and although they are small, they are quite intriguing compared to many others found in Quang Binh.